Ones tester from another forum, you might find his grow journal. Since not allowed to mention the forum, so I won't. Original post here:
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I just harvested the Cheese, the smallest of the four plants, but the bud is rock solid
One more thing I have noticed about this light and I guess its about white lights in general, is that the very bottom branches which usually produces shitty, scraggy, whispy bud. Has given me solid nugs. They're very small obviously as to be expected as they're right at the bottom. I usually just throw in the trim pile to make hash with at a later date, but I'll keep these ones for smoking
What I believe is going on here, and what I have noticed when comparing HPS light with purple LEDs is that HPS produces some green light, and although many people believe it's useless because plants reflect green light (we know this because they appear green to our eyes), they do absorb some of it. And the good thing about green light is it penetrates the canopy deeply. Charging right through leaves as well as bouncing around off them. This is why HPS light has such good penetration even in a thick canopy. Whereas the purple LEDs never seemed to get that, even with the more powerful ones. I'm thinking this is because of the lack of yellow and green light.
The SP-250 being white means it produces the whole visible spectrum, it does produce some green light and this is why I think it's getting down to the lower branches and making even the bottom buds rock solid.
Whether I'm right or wrong about the process, this light definitely makes solid nugs all the way down, so I'm a happy grower right now
That last plant was a beast. Finally dried everything and just weighed it all up ....
415g / 14.6 ounces
From just 250 watts I'm very impressed
It really is, I usually get that amount when using my 600w HPS, it's a huge electricity saving. I'd love to run two of the lights in the tent, that way I'm still saving on wattage, and I'll get a yeild twice the size.
When you add up the HPS wattage of the bulb, ballast, and air cooled hood fan, it comes to about 700w, whereas two of these SP-250 lights would be just 500w and I'd get way bigger yeilds. Plus of course the light is silent so noise is much less of a problem
I'm really impressed with this light and have recommended it countless times to lots of people, but there is one thing I would change, and that's having a 3 metre cord between the driver and main unit. That way the driver can be positioned outside the tent to save on heat. It does get quite hot. You can touch it, it's not going to burn you or anything like that, but it is adding heat to the tent which you don't want.
The driver could also be positioned inside the tent but hung up next to the exhaust fan so the heat is removed straight away "